Bonus Page 1

The school I used to go to used the same class structure, as do most schools in the UK. I used the same names of the houses (they are different now, I gather) and I was even in Queslett North myself.
Year 7 is the first year of secondary school, and is the equivalent of 6th grade in the US. Children in Year 7 are 11 - 12 years old.

This type of class structure isn't unique to boarding schools. Many schools in the UK are like this as far as I know. I went to a normal ol' comprehensive (high school). It just so happens that Gunnerkrigg Court is a boardng school.